As the need for agricultural efficiency and productivity continues to increase producers must find ways to maximize their crop's potential. Economic drivers arise from increases in fertilizer and herbicide cost, and environmental drivers call for improved pesticide and water management. Precision agriculture concepts and methods are showing great promise in meeting the world's needs for efficient agricultural practices and are becoming a staple in most row crop producers' management strategies. For instance, cotton and corn producers are using yield monitors to define and assess different zones of production and are managing these zones with variable rate application of inputs. Application of yield monitoring technologies to the production of cotton and corn has improved crop management and profits as they allow the producer to make real time adjustments to management strategy when the yield goals for zones are not met. Through such strategies producers are making progress in increasing yield while decreasing cost and field inputs. Additionally, crop yield maps provide producers with documentation of historical yield for use in substantiating insurance claims or other yield loss claims. Crop yield data is also sometimes used to support land rent values.
Hay and forages are an important part of the agricultural infrastructure particularly as livestock feed, which makes up a great deal of agricultural industry worldwide. Unfortunately, hay and forages have seen limited commercial applications of precision agriculture technology. The development of precision agriculture devices and methods that would be applicable to the harvest of windrow crops such as hay and other forage crops could improve crop management and profits in this industry similar to what has been shown for other crops.
One system has been developed in an attempt to produce yield maps from a hay field. This system weighs the bale as it comes out of the baler. Unfortunately, this system is limited to use with a large square baler. In addition, when developing a yield map by use of this system, the hay yield is not accurately distributed across the field as differences in windrow volume across the field are not accounted for. By this system, a consistent volume of hay is assigned to a windrow for a certain bale, substantially reducing map resolution. Another problem with this system is that it does not provide on-the-go yield data for the producer. Exclusive post-processing of data can be problematic in that the actions to be followed to generate the yield map may not be known be the grower and the data may have to be processed to generate the map by a third party.
Another yield monitor technology that has been examined for forage harvesting utilizes feedrollers on a silage chopper (Shinners et al., 2003). On some self-propelled forage harvesters, such as a hay windrower, impact force measure on a hinged plate have been used on the area where hay passes from the rear of the machine, correlating to yield at mowing (Savoie et al., 2002). Another study implemented yield monitoring technology on a self-propelled windrower to obtain yield data using five parameters including impact force at the swath forming shield, crop flow at the swath forming shield, roller speed, platform pitch, and pressure of platform drive motor (Shinners et al., 2003). On a forage harvester for silage, a study was conducted where five sensors were installed including a torquemeter on the PTO shaft and at the cutterhead, a load cell on the duct, a vertical displacement transducer on the feedrollers, and a capacitance-controlled oscillator installed at the end of the duct where the crop exits. Each of these sensor's responses was correlated to wet matter flow rate (Savoie et al., 2002). Feedroller pressure and displacement have been used on self-propelled silage choppers to monitor yield (Digman and Shinners, 2012). Some hay baler manufacturers have systems that can be implemented on the baler to weigh the bales after they are baled. This method utilizes load cells on the axle and the tongue of the baler.
While the above illustrate improvement in the art, room for further improvement exists. For instance, systems and methods for hay and forage yield monitoring that use remote sensing technology and capable of use with a wide variety of farm implements would be of great benefit. A need exists for yield monitoring technology devices and methods that can be used to improve management capabilities in windrow-collected crops such as hay.